What are the safe temperatures a room should be in a childcare centre with 20 sleeping children who age range from one year to 2 years old.

Red Nose does not recommend a specific room temperature, but rather recommends dressing according to the temperature.
It is not necessary to monitor the room temperature or to leave the heating or cooling on all night, as long as the baby is dressed appropriately for the room temperature.

Dress baby as you would dress yourself – comfortably warm, not hot or cold. A good way to check baby’s temperature is to feel the baby’s back or tummy, which should feel warm (don’t worry if baby’s hands and feet feel cool, this is normal).

https://rednose.org.au/article/room-temperature